Process of recovering metals.



C. l. REED.

PRocEss or RacovEm/NG METALS.

APPLICATION FILED AUG.25| 1915.

Patented 001. 3,1916.

Ill*

CHARLES J'. REED, OF GLENSIDE, PENNSYLVANIA.

PROCESS OE RECOVERING METALS.

5' and Str-te of Pennsylvania, have invented certain new and useful Improvements in Processes of Recovering Metals, of which the following` is a specification.

My invention relates to the recovery of metals from ores and other materials by electrochemical operations on aqueous solutions containing the metals.

In United States Letters Patent No.l

699,414 and No. 699,415, patented May 6, 1902, I have described a method and apparatus for manufacturing caustic alkali through the electrolytic reduction and deposition of" an alkali metal in a cathode of mercury and thesubsequent electrolytic dissolving of the alkali metal as an anode in a separate receptacle to an alkali hydroxid, the concentration of which tends to continuously increase. In the process herein described, which is not applicable to alkali metals norto any metal which cannot be electrolytically depositedin the me-I tallic state from an aqueous solution with.- out simultaneously amalgamating or alloying with mercury, I reduce in a rst operation the recoverable metal from an aqueous solution to the metallic state as an amalgamY or alloyqin a cathode of metallic mercury, and by a subsequent operation in a separate receptacle I dissolve the recovered metal from the amalgam as an anode into another. solution and simultaneously deposit the rccovered metalvin a free and purified condi#A tion on a cathode of the same metal or acathode of some other suitable conductor with which it does not form an alloy or amalgam, while compensating for the metal dissolved by local or chemical action inthe manner described below. This separate operation requires the transfer yof the amalgam ce first formed to a separate solution and practically to a separate receptacle. This transfer of the amalgam to the separate receptacle in a continuous and practical manner can be accomplished without at the same time transferring the electric current by means of the apparatus describedby me in United States Letters Patent No. '699,415, 4 above referred to. In this separate receptacle, into which the 'amalgam has been es transferred, and in whichl it acts as anl anode, .I provide a' suitable solutionA of the Specification of Letters Patent.

Patented Oct. 3, 1916.

Application filed August 25, 1915. Serial No. 47,313. i

same recoverable metal, into which the metal continuously dissolves from the amalgam now acting as anode and from which the metal is continuously deposited in the metallic state free from mercury and other impurities on a cathode of the same metal or on. a cathode of any suitable conductor with which it does not alloy. In this second electrolyte there is no continuous increase or concentration of the recoverable metal, because it is being deposited at the cathode at substantially the same rate as that at which it is dissolving at the anode. These operations enable me completely tJ removea highly electro-positive metal, like zinc, iron', cobalt, nickel and others, from an acid solution, leaving the acid pure, and at the same time separating the metal in the pure metallic state. This process I ind is adapted tothe recovery of. any metal which is electropositive to mercury and dissolves electrolytically from an amalgam without ldissolving the mercury, and is at the same time suiiicient'ly electronegative in.

character to be depositedin the free metallic state from a neutral or nearly neutral aqueous solution on a conductor wlth which ,it does not alloy or amalgamate. The prinmetals are not so easily recovered by the methods heretofore in use.

My process may be carried out bythe use of the apparatus described in U. S. Letters Patent No. 699,415, above referred to, or by the apparatus hereinafter described. Y

For a full understanding of my invention,

reference is made to the accompanying drawings, wherein- Figure 1 is a central longitudinal. section of an electrolytic apparatus for carrying the process into eect; Fig. 2 is asimilar section of a supplemental amalgam-produc.-

ing electrolytic cell; and Fig. 3 -is a central longitudinal section of an apparatus yfor distilling the amalgam in a current of an inert Referring to Fig. 1, 1 represents a receptacle of non-conductive material, subdivided by. a non-conductive partition 2, terminating above thebottom but below the surface of the amalgam to leave an aperture 3. 4 repstant f rination, and 8 is the amalgamfunctionin as anode in relation to the cathode-5.

9 is anfaqueous solution of the metal to be recovered,for example la chlorid or sulfate solution; and 10 is an aqueous solutien of the saidmetal, this latter solution remaining in substantially -constant condition as regards composition, concentration, and condition of acidity or neutrality.

Most if not all ,of the 'metals above mentioned to whichy the process is applicable chlorid of zinc, etc., between an insoluble comprises av crucible 11 iny which the alloy with 'a cover l with an outlet tube 13, for the have the property of dissolving slowly from `an amalgam by localor-purely chemical action into-the solution of the same metal in contact with the amalgam. If this tendency were not counter-acted, the final result would be that themetal deposited in the cathode 1 would not be suflicientto supply this local or chemical' dissolving and also to transmit the total current to the cathode 5. In a series arrangement of this kind, therefore, it is necessary-5to supply some additional amalgam from "time to time: this may be produced in an independent depositing cell, such as that shown tional amalgam is prepared by electrolyzing an aqueous solution 9, as the sulfate or anode 4', and a mercury cathode 7 As additional'lamalgam is supplied or transferredr to the receptacle 1, without transferring the current, the excess of depleted mercury must also be removed from this receptacle l without transferring the current. l It is not necessary to use the same salt of the metal in'both receptacles. For example,

I may use .zinc sulfate in one and z inc chlo- -Q rid in the other. 4

Myprocess is. applicable to the recovery of zinc from the ore as solution' of sulfate 'or chlorid, Vand also for the recovery ci iron,

nickel or cobalt from their ores.

'lille'i amalgam or alloy'of recoverable metal with. mercury, Aformed as abovedescribed,

may also be separated into -freemetallic mercury and the free metal by passing hydrogen`4 other reducing or. inert gas `through the high enough or melted ialloy at a temperature. to expelthe mercury. The apparatus shown in, 3 may be used for this purpose. lt

oramalgam is melted, provided 12 tightly fitting and excludingthe air, also in Fig'. 2, in whichaddiyequivalents of zinc for the purposes of this solution of metal by.

escape of the inert gas and vapor of the mercury, vand recovered metal, but that will not be detriand the gas is then passed" mental to the cyclical working ofthe proc- -ess, inasmuch as this mercury is used again to produce an amalgam of the same metal.

While lin one .of the claims specific reference is made to the recovery of zinc, it is to be understood that other metals which are electropositive to mercury, are capable of dissolving electrolytically from the amalgain without solution of the mercury and are capable of being electrodeposited from neutral or slightly acid solutions upon a cathode with which they do not alloy or amalgamate kduring the electrodeposition, the principal examples of such other metals being iron, nickel and cobalt, are "to bel regarded as invention. I-claiiiui 1; The process of recovering metals which are electropositive to mercury from an aqueous solution, which consists in electro- `depositing the metals in a cathode of merury, dissolving said metal fromI the result-` ing amalgam and simultaneously'y depositing it upon a cathode with which it does not aland compensating the local yaction from the amalgam anode by "supplying thereto the loy or amalgamate,

. 2. The process of recovering zinc from its aqueous solutions, which consists in electro depositing the metal in a cathode of mercury, dissolving the zinc from the resulting requisite additional quantities of amalgam.

amalgam Iand simultaneously depositing it y on a cathodexwvith which it does not alloy or amalgamate, andv compensating thesolu-v tion of metal by local action from the amal` Agam anodeV by supplying thereto the requisite additional quantities of amalgam.

In testimony Alll. J. SwEENEY.

whereof I ailix mypsignature .Y in presence of two witnesses. 

